Apparatus for straining fluids



May 25 1926. 1,585,817

F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS Filed July 1, 1925 5 Sheets-Sheet 1 INVENTO/PS May 25 1926. 1,585,817

F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS Filed July 1, 1925 5 Sheets-Sheet 2 /NVENTOR$.

@AJM A;

May 25 1926.

F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS 1925 5 Sheets-Sheet 4 Filed July 1 2 9 s i 7/ II I INVENTOPS.

May 25 1926. 1,585,817

F. BAILEY ET AL APPARATUS FOR STRAINING FLUIDS Filed July 1,"1925 5 Sheets-Sheet 5 Patented May 1926.

\ UNITED STATES rnANx BAILEY AND r-nnnnarcx 1,585,817 PATENT OFFICE.

HENRY JACKSON, or sournwanx, 1 LONDON, ENGLAND.

- APPARATUS FOR STRAINING FLI J IDS.

Application filed July 1, 1925. Serial No. 40,915.

In 'the specification to British patent granted to us and dated lOthFebruary 1 993, No. 3149, is described a self-cleansing strainer comprising a drum-shaped casing,

traversed axially by a horizontal shaft, whereon is mounted a wheel,,,furnished,-between its spokes, with grids which serve as straining media; and in the specification to our British patent,,dated 12th September 1918, .No. 131755,is described a self-cleans.-

"ing strainer of a similar character wherein, instead ofonly half the straining surface 7 being effective for straining purposes, a larger proportion thereof is rendered avallable for that purpose, whilst the cleansing operation is effected through a comparative- 1y small portion thereof.

Our present invention consists in certain improved methods of construction with the same object, and whereby a still larger proportion of the straining surface is rendered 'available for straining purposes. inasmuch, moreover, as the strainer-wheel, instead of rotating, is a fixture, the friction, wear and leakage which have hitherto occurred be- "tween the periphery of the straining wheel and its casing are avoided.

Apparatus adapted for carrying our 1nvention into effect is illustrated in the accompanying drawings, whereof 1 is a vertical section and Fig. 2 a face view, partly in section, of a strainer designed for workingunder pressure, that is to say, where the fluid to be strained-assumed to be waterpasses through a force-pump prior to enter-- in the'strainer. h

Fig. 3 is an edge view and Figs. 4 and 5 are face views of ratchet and pawl mechanisms for imparting step-by-step rotatlve movements to certain appliances hereinafter described. I Fig. 6 showsin side elevation and Figs. 7 and 8 in vertical section valve apparatus for controlling the discharge of the flushing water. s

Fig. 9 is a side elevation and Fi.10 a

face view of ratchet and pawl mec anismadapted to enable the strainer to be worked in either direction of rotation.

Fig. 11 is a diagrammatic view showing the assemblage of certain parts in their working positions.

Assuming the appliance to be arranged on the delivery side of a pump, and there fore to work under pressure, the apparatus comprises a cylindr cal chamberwherein is fixed a circular strainer, preferably formed as a disc at with radial spokes a; the spaces between the spokes constituting sectorshaped chambers the backs, of which are formed of grids a, the fronts of the said chambers being open. On the inlet 6, or unstrained-water side vof the strainer-disc, s mounted a box-like ch mber 0 correspondmg in form substantially with that of one of the sector-shaped grids; the face of the box presented to the strainer disc being open. For balancing purposes, we prefer to employ two such box-like chambers-hereinafter termed cleanser-boxes-and arrange them to extend radially from opposite sides ofa slowly rotating hollow shaft d. A

single cleanser-box may however be employed and a counter-balance weight sub stituted for the cleanser-box radially opposite. As each cleanser-box arrives over the straining face of one of the grid furnished strainer chambers, a portion of the Water which has been strained on its passage through other portions of the strainer disc returns through the strainer chamber temporarily covered by the cleanser-box and flushes the debris off the receiving face. of the grid pertaining thereto; this water, together with the flushed'oflf debris, escaping through the cleanser-box c and hollow shaft Q at back to the source of supply or elsewhere.

The movements of the cleanser-box or boxes are intermittent; and whilst such movements are taking place, it is desirable, in order to reduce friction, to relieve them, so far-as possible, from the pressure upon their backs, due to the impact of the incomzng water. VVith-this object, we arrange, at

--the back of each, a shield e which moves in or the latter may be operated by means of v suitably timed but otherwise independent mechanism.

The discharge from the cleanser-box or boxes by way of the hollow shaft d is controlled by an intermittently acting valve which is closed during the angular movement of the cleanser-box, and is only reopened when the latter is properly seated u ai'nst the rid-furnished strainln cham-.

her next in order.

The cleanser-box is mounted on the hollow shaft d but is driven from the shaft f by means of the shield e mounted thereon. Means for operating the shaft f are illustrated in Figs. 3, 4 and 5, and comprise a disc, whereof the periphery is formed with two sets of teeth, the two sets pointing in opposite directions, and a vibrating lever furnished with two pawls, one for each set of teeth. As shown in the edge view Fig. 3 and face views Figs. 4 and 5, the disc carries two sets of ratchet teeth g 9 and pawls h h for working therewith are pivotally' mounted on the vibrating lever or pair of levers j. Upon the lever y moving from left to right, the pawl it rotates the ratchet bearing the teeth 7 through an arc subtending two teeth. When however the lever j is moved the same angular distance from right to left, the ratchet bearing the teeth 9 is rotated in the reverse direction, but only through an arc corresponding with one tooth by reason of its roller-furnished tail-piece coming into contact with an inwardly projecting portion of the casing 70, with the effect that the pawl is tripped out of engagement with the ratchet upon the latter having been rotated through an arc correspondmg with one tooth only.

The gradual rotation of the cleanser-box in a forward direction is effected by the engagement therewith of the lugs 6 carried forward and backward movements.

by the shield e, and the rotative movement of the latter is dependent upon the action of the pair of ratchets whence it derives boph 11 moving from opposite'one strainer-chamber to opposite the next, the cleanser-box and its shi d move in unison, the latter protecting the former from the impact of the water supply. Having arrived at this position, the shle d moves back one-ste thereby uncovering the strainer-box and lie to the full water pressure. The face of the grid pertaining to that strainer chamber having been flushed by the return flow of water, the shield again advances one step,

' so as to cover the strainer-borgand continues aving it exposed,

. pipe arranged between two of the strainerchambers. In either case,'its outlet is conrolled by a valve operated from the machine by a lever, the working of which is suitably timed. I A valve suitable for controlling the discharge from the straining chamber is illustrated in Figs. 6, 7 and 8. The valve is of V-section, has a shut-ofi' flap Z and a pressure-balancing flap Z, the pressure-water gaining access to the back of the latter flap by way of the passage Z with a straining grid. The valve is mounted upon a spindle Z which passes through glands, arranged in the sides of the valve-casing, and .is provided at one end with an arm Z and at the other end with an arm Z which latter is furnished with an adjustable weight for balancing purposes. In order to ensure a quick and wide opening for the discharge of debris, and in order to provide against the risk of hard substances lodging under the valve seating and causing damage to the mechanism, this valve is not rigidly connected, but is operated through the agency of a tension-spring Z which extends from the outer extremity of the arm Z. to the extremity of alever Z pivoted at Z In the position shown in F1m"6,the tension of the spring tends to hold the flap Z of the valve closed upon its seating; but upon the lever Z being -vibrated, the line along which the spring exerts its .tensional effort is transferred to the opposite side of the axis of the valvespindle Z with the effect that the valve suddenly opens. In like manner, upon the lever yond its central position, the valve suddenly closes. The operation of this valve is timed to open and close whilst the cleanser-box is seated and remains stationary against one of the strainer-chambers, and the valve remains closed during the movement of the cleanser-box to a position opposite the strainer-chamber next in rotation.

10! Z being moved in the opposite direction be- In order to admit of the strainer-box or boxes being rotated in either direction, we employ a ratchet-wheel formed with recesses in its face, asillustrated in edge view in Fig. 9 and in face view in Fig. 10. A centrally pivoted ring formed with a radially projecting arm 7 is oscillated by means of a reciprocating rod 7'. On the o posite sides of the ring 7' are two laterall y proj eating spindles on each of which is mounted a pawl it provided with a weighted arm k arranged at such an angle that, when thrown to one or to the other side of the vertical, the pawl will engage with the recesses-q formed in the face of the wheel or will be held out of engagement therewith. In the latter condition, the pawl on the opposite side is turned about its pivot so as to throw its weighted arm outwards, whereupon its operative arm becomes engaged with away from the face of the strainin the recesses formed in the face of the wheel 9 and the latter is rotated in the opposite direction.

It will be observed that, owing to the oblique angle at which the pawl 72, actsupon the disc 9 the latter is subjected to a lateral thrust which tends. to, force the cleansergbox isc;

thereby diminishing the pressure an during movement, reducing the friction and wear between their faces.

As regards each of the pawl fittings, a second pawl-arm may be added on the opposite side of each of the pawl-pivots, as shown in dotted lines. Under such circumstances, two'pawl-arms become operative in either direction of rotation, the total thrust upon the disc, rotatively and laterally, being divided between them.

In Fig. 11 is illustrated the manner in which certain parts hereinbefore described in detail are or may be assembled; the arm j, or j for operating the ratchet-pawls h,

h being connected to a revolving crank r, to wlnch is also connected the lever Z for operating the valve l for .controlling the 1. A self-cleansing strainer comprising a" chamber enclosing a circular straining medium which is stationary and is divided into numerous sectors fitted with straining grids over the faces of winch a sector-shape cleanser-boa rotates and, as it arrives over each grid-furnished sector, forms a closed chamber through which a stream of water or other fluid is caused to pass from the back of the grid for the purpose of flushing OE and removing the dbris previously de posited on its face.

2. In a self-cleansing strainer of the character defined in claim 1, the combinathe direction of rotation thereof to be reversed; same comprising a wheel having arranged around its face equally distributed recesses adapted for engagement with one or the other (or both) of two pivoted pawls arranged on opposite sides of its centre; each of these pawls being furnished with a counterweight disposed in such a manner as to hold the pawl in operative engagement or out of engagement with the notches in the face of the wheel, and being mounted in such a man-- neras to exert a lateral thrust uponthe said wheel.

.4. In connection with a self-cleansing strainer of the character defined in claim 1,

the employment of a partially balanced valve for controlling the discharge of the water employed for flushing the strainergrids; such valve beingadapted to open or close full and suddenly upon the lever, whereby 1t is operated, entering upon the second half ofits stroke. 1

FRANK BAILEY. FREDERICK HENRY JACKSON. 

